DE102015209325A1 - Hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer - Google Patents

Abstract

Disclosed is a hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer (2), with a first flow path (6) and a second flow path (10) for the pressure medium supply of the hydraulic consumer (2). Furthermore, the hydraulic arrangement has a lowering brake valve arrangement (12) in the second flow path (10), which contains a regulating orifice (18), by means of which a regeneration volume flow can be controlled, which can be regenerated from the second flow path (10) into the first flow path (6) is. The regeneration volume flow fed into the first flow path (6) is led directly to the hydraulic consumer (2). Alternatively, the regeneration volume flow is fed between a valve arranged downstream of a pressure medium source and the hydraulic consumer (2) into the first flow path (6). Alternatively, the regeneration volume flow between an individual pressure compensator (52) and a metering orifice (54) is fed into the first flow path (6).

Description

Field of the invention

The invention relates to a hydraulic arrangement according to the preamble of patent claim 1.

Background of the invention

In known hydraulic control units for excavators or backhoe loaders is achieved by the mechanical adjustment of the notch geometries of inlet and Rücklaufmessblenden that the speed of the consumer is specified by the inlet flow and the cavity of the cylinder is not kavitiert. For this purpose, a vote must be made between supply and return orifice in the way that the return flow rate would be lower for driving loads (active loads), than the adjusted cylinder flow ratio inlet flow. The tuning of the blinds of a consumer to e.g. An excavator depends, among other things, on the kinematics of the working arm (position of the center of gravity, position of the pivot points, transmission ratios of the coupling mechanisms, etc.), the applied loads and the geometric sizes of the cylinder. For this reason, the notches of the respective panels must be adjusted individually for each consumer. In known valves with a slide (unresolved control edges) the notches are milled during commissioning using a mobile milling machine in the respective sample pushers, examined for their effect and possibly further optimized. This iterative process is very time-consuming and labor-intensive and also increases the variance of mechanical components in the production process of hydraulic directional valves with a slide for the common realization of all feed and return flow orifices on this.

In the DE 10 2012 203 386 A1 and the DE 10 2012 203 387 A1 To avoid these disadvantages valve assemblies are presented with dissolved construction between the assignment of the inlet and return flow orifices. The inlet valves are in this case carried out by electrically controllable valves in seat design, with each consumer connection an inlet valve can be assigned. The return valves are formed by so-called Senkbremsventile, as for example in the DE 10 2012 220 863 A1 to be discribed.

However, arrangements with lowering brake valves in the return line tend to be unstable, which can lead to strong fluctuations in the load pressure curve. To avoid this disadvantage, it is known to prevent a pressure build-up and thus a system gain, which can lead to the unstable behavior, by means of various damping diaphragms. Since the operating principle of the use of the damping diaphragms is essentially based on a low-pass behavior, the damper diaphragm diameters must be made very small in order to be able to filter the correspondingly low frequencies (for example, with a boom of a wheeled excavator approx. 1.5 Hz). However, the damping diaphragm diameter can not be chosen arbitrarily small on the one hand for reasons of production and on the other hand because of the decreasing diameter increased risk of contamination and thus limited functionality. In addition, damping diaphragms considerably reduce the system dynamics, so that the setpoint specifications of the operator are possibly converted into the desired movements of the hydraulic consumers with a significant delay. Running the cylinder when releasing the joystick, and thus with actually immediate removal of the setpoint signal, may be the result. This condition is not desired by either an OEM or a user.

In the DE 10 2012 220 863 A1 a lowering brake valve assembly is disclosed in the return, which leads the load pressure in the return passage by a diaphragm assembly delayed in time to the spring-loaded end face of the Senkbremsventilschiebers. This is to increase the system stability without having to use diaphragms with too small diaphragm cross-section. Since the load pressure in the return line acts, inter alia, directly on the annular surface of the sealing seat of the main stage, a delaying differentiating behavior (DT behavior) arises based on the resulting pressure force, which has a stabilizing effect on the overall system behavior.

If a regeneration is realized in such an arrangement, the entire return flow is regenerated via the lowering brake valve spool and a check valve in the inlet. However, in order to operate the hydraulic load even with a passive load, an additional lowering brake valve must be provided in the return, which connects the return to a pressure medium sink and the opening pressure is significantly greater than that of the lowering brake valve used for the regeneration.

In contrast, it is the object of the present invention to provide a hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer, in which an effective regeneration in a simple manner can be realized.

This object is achieved by a hydraulic arrangement having the features of patent claim 1.

Advantageous developments of the invention are described in the subclaims. A hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer according to the present invention includes a first flow path and a second flow path to the pressure medium supply of the hydraulic consumer. It further includes a counterbalance valve arrangement in the second flow path having a metering orifice plate by means of which a regeneration flow rate controllable from the second flow path into the first flow path is controllable. The regeneration volume flow fed into the first flow path is led directly to the hydraulic consumer. In particular, the regeneration volume flow fed into the first flow path is guided to the hydraulic consumer without the interposition of valves. Alternatively, the regeneration flow rate is fed between a valve located downstream of a pressure medium source and the hydraulic load in the first flow path. Alternatively, the regeneration volume flow between an individual pressure compensator and a metering orifice is fed into the first flow path.

Due to the direct supply of the regeneration volume flow in the first flow path to the hydraulic consumer, that is, by means of the in the first flow path without the interposition of valves supplied to the hydraulic consumer regeneration volume flow, a regeneration is realized in a simple manner in which the regeneration due to the existing throttle points between injection point and hydraulic consumer is particularly effective. An increase in an operating speed of the hydraulic consumer with an otherwise constant inflow volume flow, in particular a constant load of a pressure medium source, is comparatively higher.

Furthermore, it is an advantage of the present invention that, by feeding the regeneration volume flow between an individual pressure balance and a metering orifice into the first flow path, the regeneration volume flow is fed in front of the metering orifice, since thus only a partial volume flow has to be supplied by the individual pressure balance, by means of the required pressure drop across the inlet orifice is set. Consequently, a resulting inlet volume flow is predetermined only by an opening cross-section of the metering orifice and thus adjustable or adjustable independently of the load.

Advantageously, the regeneration volume flow is fed via a regeneration check valve into the first flow path, which blocks in the direction of the lowering brake valve arrangement. Thus, the flow direction of the regeneration volume flow is limited to one direction to the hydraulic consumer and in the operation of the hydraulic consumer, an undesired flow of pressure medium from the pressure medium source to the lowering brake valve arrangement is prevented.

Advantageously, the lowering brake valve arrangement has a bypass orifice or bypass orifice with a fluid connection to a pressure-medium sink. The bypass orifice is advantageously followed by the metering orifice in a fluidic manner. In particular, the bypass orifice is connected fluidically or in parallel in series with the control orifice plate.

With this construction according to the invention, a hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer is provided, which has a more stable operating behavior and with which a large part of the return flow volume can be regenerated. Hereby, the advantages of a Senkbremsanordnung, so avoiding cavitation in an inlet side at an active load without costly adaptation of inlet and Rücklaufmessblenden (especially in unresolved construction), with the benefits of regeneration, ie increasing an operating speed of the hydraulic consumer or reducing a volume flow in the inlet side to connect.

Advantageously, an opening cross section of the bypass orifice is proportional to an opening cross section of the Regelmessblende, in particular proportionally adjustable. This further supports the achievement of more stable performance and the ability to regenerate much of the return flow.

Advantageously, the lowering brake valve arrangement is arranged independently of a direction of movement of the hydraulic consumer in a return flow path. Further advantageously, the regeneration volume flow is fed independently of the direction of movement of the hydraulic consumer in a Zulaufströmungspfad. This can be achieved, in particular, by means of a directional valve, precisely one lowering brake valve arrangement being connected such that it is arranged independently of a direction of movement of the hydraulic consumer in a return flow path. Alternatively, this can be achieved in that two Senkbremsventilanordnungen are interconnected such that depending on the direction of movement of the hydraulic consumer, only that is activated, which is arranged in the return flow path and that is deactivated, which is arranged in the inflow flow path.

Advantageously, the lowering brake valve arrangement has a lowering brake valve, the valve slide of which is acted upon by a closing spring in the direction of closed positions in which a return volume flow and thus the regeneration volume flow is interrupted. In particular, the lowering brake valve further has open positions in which the return flow is at least partially passed as a regeneration volume flow through the control orifice through the lowering brake valve and wherein the return flow is at least partially passed through the bypass orifice to the pressure fluid sink. In particular, in the hydraulic arrangement according to the invention, the entire return flow volume can never be regenerated - a part of the return flow volume is always directed via the bypass orifice to the pressure medium sink. In particular, the lowering brake valve is designed as a continuously adjustable valve.

Advantageously, an end face of the valve slide, in particular an impact element acting on the end face of the valve slide, can be acted upon by a throttle with a pressure means for piloting, which in particular is tapped off from the first flow path or the inlet flow path. Thus, a pressure build-up speed at the end face of the valve spool, in particular at the impact element - and thus in particular a system gain - reduced, which further contributes to the stabilization of the hydraulic arrangement. In particular, by means of one or more of the throttles, a control line for the pressure medium for overriding relieved, in which it is arranged / are. Thus, in the absence of actuation of a control device for the hydraulic arrangement, that is, when the hydraulic consumer is to remain in its current position, an uncontrolled pressure build-up by leakage can be avoided. In particular, between two of the arranged in the control line for the pressure means for controlling throttles a branch to Druckmittelsenke provided with another throttle, wherein the valve spool after the other throttle with a pressure medium from the branch, in particular with a pressure medium of the pressure medium sink, acted upon in its opening direction is.

Advantageously, the closing spring is arranged in a rear space bounded by a further end face of the valve slide. Further advantageously, a fluid connection of the rear space with the pressure medium sink can be interrupted by means of a shut-off device. In non-actuation of the control device for the hydraulic arrangement, that is, when the hydraulic load is to remain in its current position, thus a discharge of pressure medium from the rear space in the pressure medium sink prevented, thus ensuring that the hydraulic consumer is actually in its current position remains.

Advantageously, the shut-off device, which is designed in particular as a seat valve, a valve body which is acted upon by a compression spring in the closing direction and which is displaceable in the opening direction by means of an actuatable by a pressure medium in the Zulaufströmungspfad impingement device, in particular a Aufstoßstange or a poppet. By means of the movement of the valve body in the opening direction, the fluid connection of the rear space can be made with the pressure medium sink, which allows a flow of pressure fluid from the rear space and thus allows movement of the valve spool of Senkbremsventils in the opening direction.

Since the lowering brake valve is controlled by adjoining pressures, ie without direct influence from the outside, such influence is advantageously created with the shut-off device. If, for example, a pulling load (= an active load, for example a mass to be lowered, whose weight acts in the working direction) is present and the control device for the hydraulic arrangement is not actuated, the lowering brake valve is in particular closed by means of the closing spring, in order to prevent undesired lowering of the load avoid and keep the current position of the hydraulic consumer - and thus the load -. If such a load to be lowered, the shut-off device cooperates with the impact device such that the impact device actuates the shut-off device in its opening direction and allows the outflow of pressure medium from the rear space into the pressure medium sink. Thus, the valve spool of the lowering brake valve is displaceable in its opening direction and thus a pressure medium connection of the hydraulic consumer to the pressure medium sink produced.

Advantageously, in a passive load (for example, a mass to be lifted, whose weight counteracts the working direction), the valve slide is controlled in its open position and the bypass orifice to the pressure medium sink is fully open. The return flow is completely conveyed into the pressure medium sink, since the regeneration check valve, via which the regeneration flow is otherwise fed into the first flow path, remains closed due to the prevailing pressure conditions.

Advantageously, the shut-off device is formed separately from the lowering brake valve. Alternatively, the shut-off device may be arranged in the valve spool. This is a smaller footprint achieved. Furthermore, this reduces a number of the components to be machined.

Advantageously, the valve body is designed as a pressure balanced slide with a pressure equalization hole. About the pressure compensating bore is a pressure equalization of a Schieberringraums the shut-off device with a limited of an end face of the slide chamber in which the compression spring is arranged allows. Thus, movement of the valve body in its opening direction is permitted as soon as the impactor acts on the valve body in its opening direction. Alternatively, the valve body may be formed as a sealing cone.

Advantageously, an overlap of the slide in its bore is so large that occurring leaks remain as small as possible over the annular gap between the slide and bore. For example, the coverage is at least twice as large as a diameter of the valve body. In particular, an overlap of the slide is dimensioned in its bore such that an expected amount of leakage in an annular gap between the slide and the bore can be accommodated. Thus, leakage of the shut-off device into a pressure medium sink can be reduced to a minimum, if not avoidable.

Advantageously, by means of a pressure divider arrangement, which in particular contains two pressure divider chokes and between which an intermediate pressure branch is provided, an intermediate pressure medium tapped, the pressure acting thereby has a value between a pressure acting in the return flow path and a pressure acting in the pressure medium sink pressure. Such a pressure divider arrangement is for example in the DE 10 2012 220 863 A1 described, whose contents are expressly referred to here. Advantageously, the pressure divider chokes are designed as diaphragms. Thus, a temperature influence is avoidable as possible. In particular, the two pressure divider throttles are arranged in a branch of the return flow path fluidically connected to the pressure medium sink, the intermediate pressure branch being connected to the lowering brake valve between the two pressure divider throttles.

Advantageously, an end face of the sealing cone is acted upon by the pressure divider arrangement with pressure medium from the return flow path. As a result, the sealing cone is pressed into its sealing seat, whereby the shut-off device is very low-leakage.

Advantageously, the sealing cone, for example for lifting a load, can be pressed out of its sealing seat with the topping piston acted on by pressure medium from the inlet flow path. Thus, while pressure medium between the two pressure divider throttles in the pressure medium sink can be discharged, but via a arranged in the Zwischendruckabzweigung intermediate pressure throttle valve spool with pressure medium of the Zwischendruckabzweigung is applied in the closing direction and thus the valve spool is force balanced. That is, in this condition, the valve spool is not yet moved out of position but is too easily moved out of position by further movement of the poppet on the valve spool.

Advantageously, the valve spool is statically balanced due to the force acting in the intermediate pressure branch intermediate pressure, since acting in the return flow path load directly (without a throttle) acts in the opening direction on the valve spool, whereas pressure means the Zwischendruckabzweigung time delayed (via the pressure divider throttles and the intermediate pressure throttle) on the valve spool in its closing direction acts. Based on the resulting compressive forces, a delay-differentiating (DT) behavior results, which has a stability-promoting effect on the system behavior of the hydraulic arrangement.

Advantageously, pressure medium for controlling the lowering brake valve after the metering orifice is tapped from the inlet flow path. In particular, the individual pressure compensator is acted upon by the pressure medium tapped from the inflow flow path after the metering orifice in its closing direction. Alternatively, pressure medium for controlling the lowering brake valve between an individual pressure balance and the metering orifice may be tapped from the inlet flow path. In particular, the individual pressure compensator is acted upon by the pressure medium tapped by the inlet pressure flow path between the individual pressure balance and the metering orifice in its opening direction. Thus, a pressure acting between the individual pressure compensator and the metering orifice is controlled by the lowering brake valve, which pressure is identical to a pressure acting at a feed location of the regeneration flow, since in this case the regeneration flow is fed between the individual pressure balance and the metering orifice into the first flow path. Thereby, a maximum pressure difference between the return flow path and the feed location is set. The load-independent adjustment of the working speed of the hydraulic load is maintained even with this interconnection.

Advantageously, the valve spool is acted upon by pressure means for controlling a first throttle check valve, which blocks in the direction of the inlet flow path. Further advantageously, the valve spool is acted upon by pressure medium for controlling via a second throttle check valve, which blocks in the direction of the return flow path. In particular, slow down or dampen the throttle check valves (quasi "cross over") a movement of the valve spool of Senkbremsventils. By using throttle check valves, an effective opening cross-section of a throttle function of the throttle check valve can be further reduced than is the case with, for example, drilled diaphragms, since there is virtually no risk of blockage in the case of a throttle check valve. Thus, the use of Senkbremsventilanordnung or the lowering brake valve is also feasible in otherwise critical hydraulic consumers with high inertia and / or large hydraulic capacity.

Advantageously, a branch, in particular with a further throttle, is provided to the pressure medium sink on a control line between the throttle or the first throttle check valve and the inlet flow path.

In particular, the hydraulic arrangement is hydraulically interconnected with an inlet valve in open center (OC) throttle control or in load sensing (LS) or load pressure independent flow distribution (LUDV) control.

Brief description of the drawings

Several embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

1 1 is a circuit diagram of a first embodiment of a hydraulic system connected to a hydraulic consumer according to the present invention;

2 a cross-section of a second embodiment of a hydraulic arrangement according to the invention with a separate shut-off device for a leakage amount from a back space for a closing spring, and

3 a cross-section of a third embodiment of a hydraulic arrangement according to the invention with a valve disposed in a valve closure device for a leakage amount from a back space for a closing spring,

4 4 is a circuit diagram of a fourth exemplary embodiment of a hydraulic system connected to a hydraulic consumer according to the present invention;

5 1 is a circuit diagram of a fifth embodiment of a hydraulic system connected to a hydraulic consumer according to the present invention;

6 a circuit diagram of a sixth embodiment of a connected to a hydraulic consumer hydraulic arrangement according to the present invention, and

7 a diagram in which different implementations of Senkbremsanordnungen with respect to their system stability compared to the hydraulic arrangement according to the invention are shown.

Detailed description of the illustrated embodiments

In the in 1 illustrated circuit diagram of a first embodiment of a hydraulic arrangement 1 according to the present invention is a hydraulic consumer 2 , here a differential cylinder, with a piston chamber 4 via a first flow path 6 and a controller (not shown) for the differential cylinder 2 , For example, an inlet valve, with a (not shown) pressure fluid source fluidly connected. The annulus 8th of the differential cylinder 2 is via a second flow path 10 and via a lowering brake valve arrangement 12 with a pressure medium sink 14 fluidically connectable.

The lowering brake valve arrangement 12 has a lowering brake valve 16 , Here designed as a continuously adjustable 3/2-way valve having open positions and closed positions. In the open positions is a Regelmitblende 18 and a fluidic downstream bypass orifice 20 provided, both with an adjustable opening cross-section. In the open positions, the control orifice is 18 fluidic with the feed flow path 6 connected and the bypass orifice 20 with the pressure medium sink 14 , In a closed position is a first check valve 22 provided in the direction of the Zulaufströmungspfads 6 locks and so (in the illustrated first direction of movement 23 ) a fluid connection of the annulus 8th with the inlet flow path 6 interrupts. For reasons of clarity, reference has been made to the representation of elements for a second direction of movement of the differential cylinder 2 omitted, for example, a directional control valve, with which the working connections of the differential cylinder 2 are switchable such that the first flow path 6 regardless of the direction of movement of the differential cylinder 2 is always a Zulaufströmungspfad and the second flow path 10 always a return flow path.

A valve spool 26 the lowering brake valve 16 is acted upon in the closing direction by means of a closing spring 24 and by means of a pressure medium from a pressure divider arrangement 30 Intermediate pressure medium, which via an intermediate pressure throttle 32 on the valve spool 26 acts. A value of that by the Intermediate pressure acting intermediate pressure is between one in the return flow path 10 effective pressure and a pressure in the pressure medium sink 14 , The check valve 22 Can functionally from a seat of the valve spool 26 be adopted so that it does not have to be present as a separate component.

The pressure divider arrangement 30 is in one with the pressure medium sink 14 fluidically connected branch of the return flow path 10 provided and contains two pressure divider chokes 34 , Between the two pressure divider chokes 34 is an intermediate pressure branch 35 to the lowering brake valve 16 connected, by means of an intermediate pressure medium is tapped.

The valve spool 26 is acted upon in the opening direction by a pressure medium in the return flow path 10 , a pressure medium in the pressure medium sink 14 and over two throttles 36 with a pressure means for controlling that of the inflow flow path 6 is tapped.

The two throttles 36 are in a branch from the feed flow path 6 to the lowering brake valve 16 arranged. Between the two throttles 36 is a pressure medium tapped, thereby acting pressure after another throttle 38 the pressure corresponding to that in the pressure medium sink 14 acting pressure prevails.

As soon as the valve spool 26 the lowering brake valve 16 because of the forces acting on it by the pressure medium loading or the closing spring described above 24 is moved from its open positions in the direction of its closed positions, a return flow over the Regelmessblende 18 and a regeneration check valve 40 in the feed flow path 6 regenerable. Partially, the return flow is via the bypass orifice 20 in the pressure medium sink 14 directed. Depending on the design of the control orifice 18 and the bypass orifice 20 For example, a higher bypass flow (larger bypass gland cross-section) can be set to increase system stability, or a lower bypass flow (smaller bypass gland cross-section) can be set, which increases the regeneration flow rate but also reduces system stability. For passive loads, the valve spool 26 controlled in its open position and the bypass orifice 20 to the pressure medium sink 14 is fully open. The return flow is completely in the pressure medium sinks 14 promoted because the regeneration check valve 40 remains closed due to the prevailing pressure conditions.

This in 2 illustrated second embodiment differs from the in 1 illustrated and described above first embodiment by a separately formed shut-off device 42 , with which a fluid connection of a back space 44 for a closing spring 24 with the pressure medium sink 14 is interruptible.

The separately formed shut-off device 42 , designed here as a seat valve, has a valve body 46 , which is designed as a slide with a pressure equalization hole. On the slide 46 acts an impact device 48 , designed here as a Aufstoßstange. The slider 46 is by means of a compression spring 50 acted upon in its closing direction and displaceable in its opening direction by means of the push rod actuated by an inlet pressure.

By means of the shut-off device 42 interrupted fluid communication between the rear space 44 and the pressure medium sink 14 is an outflow of pressure fluid from the backspace 44 in the pressure medium sink 14 prevents and, for example, a load held in its current position.

By means of the movement of the slider 46 in the opening direction, the closed back space 44 be opened, causing a drainage of pressure fluid from the backspace 44 via a valve spool space 45 and a slider annulus 47 allows and thus a movement of the valve spool 26 the lowering brake valve 16 in the opening direction permits.

This in 3 illustrated third embodiment differs from that in 2 illustrated and described above second embodiment by a in the valve spool 26 arranged shut-off device 42 , with which a fluid connection of a back space 44 for a closing spring 24 with the pressure medium sink 14 is interruptible.

The impact device 48 is designed here as a pounding piston. The valve body 46 is designed here as a sealing cone, by the compression spring 50 is acted upon in the closing direction. Compared to the in 2 shown separate shut-off device 42 is the one in the valve spool 26 arranged shut-off device 42 space-saving and cheaper to manufacture, since the number of components to be machined is reduced.

By means of the stepped piston 48 is first the sealing cone 46 from its seat in its opening direction can be lifted, the valve slide because of the on the valve spool 26 acting intermediate pressure means throttling between the pressure divider described above 34 is tapped, remains balanced in peace. First with one further movement of the pounding piston 48 the pounding piston arrives 48 with the valve slide 26 in plant, causing the valve spool 26 then slightly slidable in the direction of its open positions.

This in 4 illustrated fourth embodiment differs from the in 1 illustrated and described above first embodiment in that the regeneration flow between an individual pressure balance 52 and a metering orifice 54 in the feed flow path 6 is fed.

The individual pressure balance 52 is with the after the metering orifice 54 from the feed flow path 6 tapped pressure applied in their closing direction and with the between the individual pressure compensator 52 and the metering orifice 54 from the feed flow path 6 tapped pressure applied in their opening direction.

The individual pressure compensator is acted upon in its closing direction with the pressure medium tapped from the inlet flow path after the metering orifice. In its opening direction, the individual pressure compensator is acted upon with pressure medium tapped by the inlet pressure flow path between the individual pressure balance and the metering orifice. The individual pressure compensator is spring loaded in its opening direction acted upon. The metering orifice is spring loaded in its closing direction acted upon.

This in 5 illustrated fifth embodiment differs from the in 4 illustrated and described above fourth embodiment in that pressure means for controlling the Senkbremsventils 16 between the individual pressure balance 52 and the metering orifice 54 from the feed flow path 6 is tapped.

The pressure between the individual pressure balance and the metering orifice is identical to the pressure at the point of supply of the regeneration volume flow, whereby a maximum pressure difference between the return flow path and the feed location is set.

This in 6 illustrated sixth embodiment differs from that in 1 illustrated and described above first embodiment characterized in that throttle check valves 56 . 58 instead of one of the above-described throttle 36 or instead of the intermediate pressure throttle 32 are used.

The functioning of the throttle check valves 56 . 58 is shown in terms of circuitry by means of a parallel connection each of a check valve and a throttle.

The throttle check valves 56 . 58 slow or dampen movement of the valve spool 26 the lowering brake valve 16 because a pressure medium flow coming from the valve spool 26 is displaced, can flow exclusively through the check valve in parallel throttle. In the pressurization, however, no delay takes place, since the pressure can flow through the opening in this direction check valve of the parallel-connected throttle.

Disclosed is a hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer, in which a bypass measuring orifice of a regulating orifice is fluidly connected downstream in a lowering brake valve arrangement with a lowering brake valve. Thus, a large part of a return flow rate can be regenerated into a feed flow path. Depending on the opening cross-section of the control orifice and the bypass orifice plate, a higher bypass flow can be set and thus a system stability can be increased, or a lower bypass flow can be set, thus increasing the regeneration volume flow but reducing system stability. As a result, a stable interconnection of a lowering brake valve arrangement is created, in which a large part of the return flow volume can be regenerated into the inlet flow path.

In 7 a diagram is shown in which different implementations of Senkbremsanordnungen with respect to their system stability compared to the hydraulic arrangement according to the invention are shown.

Above a dividing line 60 is an unstable operating area located below the dividing line 60 is a stable operating area located. On the abscissa, a cylinder velocity in [m / s] is plotted, the ordinate shows a (system) gain in [dB], where the dividing line 60 corresponds to a value of 0 dB. The unstable operating range is a range of positive dB values, the stable operating range is a range of negative dB values.

The various curves show an amplitude reserve in the form of the system gain of an open controlled system with a 180 ° phase offset as a function of the cylinder speed, with the same applied intake volume flow values in each case.

The first turn 62 shows the 3/2-way lowering brake valve with regeneration function of the hydraulic arrangement according to the invention, the second curve 64 shows a 2/2-way lowering valve as a regeneration valve and the third curve 66 shows a 2/2-way lowering brake valve without regeneration function.

The 3/2-way lowering brake valve according to the present invention achieves a significantly higher stability reserve over its entire operating range (= greater distance from the dividing line 60 ) as the 2/2-way lowering brake valves with or without regeneration function. Especially at higher cylinder speeds, the stability reserve of the 3/2-way lowering brake valve according to the invention is sometimes significantly higher than the stability reserves of the 2/2-way lowering brake valves with or without regeneration function.

LIST OF REFERENCE NUMBERS

1

Hydraulic arrangement

2

hydraulic consumer (differential cylinder)

4

piston chamber

6

first flow path (inlet flow path)

8th

annulus

10

second flow path (return flow path)

12

Senkbremsventilanordnung

14

Pressure medium sink

16

lowering valve

18

Usually Orifice

20

Bypass Orifice

22

check valve

24

closing spring

26

valve slide

28

first direction of movement

30

Pressure divider arrangement

32

Intermediate pressure throttle

34

Pressure divider choke

35

Zwischendruckabzweigung

36

throttle

38

another throttle

40

Regeneration check valve

42

shut-off

44

backcourt

45

Spool valve annulus

46

Valve body (slide)

47

Slide annulus

48

transferring device

50

compression spring

52

Individual pressure compensator

54

metering orifice

56

first throttle check valve

58

second throttle check valve

60

parting line

62

first curve - inventive 3/2-way lowering brake valve

64

second curve - 2/2-way lowering brake valve as regeneration valve

66

third turn - 2/2-way lowering brake valve without regeneration function

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012203386 A1 [0003]
• DE 102012203387 A1 [0003]
• DE 102012220863 A1 [0003, 0005, 0026]

Claims (15)

Hydraulic arrangement for the regeneration of pressure medium of a hydraulic consumer ( 2 ), with a first flow path ( 6 ) and a second flow path ( 10 ) to the pressure medium supply of the hydraulic consumer ( 2 ), a lowering brake valve arrangement ( 12 ) in the second flow path ( 10 ), which has a control orifice ( 18 ), by means of which a regeneration volume flow can be controlled, which is controlled by the second flow path (FIG. 10 ) in the first flow path ( 6 ) is regenerable, characterized in that in the first flow path ( 6 ) fed regeneration volume flow directly to the hydraulic consumer ( 2 ) or that the regeneration volume flow between a downstream of a pressure medium source valve arranged and the hydraulic consumer ( 2 ) in the first flow path ( 6 ), or that the regeneration volume flow between an individual pressure balance ( 52 ) and a metering orifice ( 54 ) in the first flow path ( 6 ) is fed. Hydraulic arrangement according to claim 1, wherein the lowering brake valve arrangement ( 12 ) a bypass measuring diaphragm ( 20 ) with a fluid connection to a pressure medium sink ( 14 ), and wherein the bypass orifice ( 20 ) the control orifice ( 18 ) fluidly connected downstream or fluidly connected in parallel thereto. Hydraulic arrangement according to claim 1 or 2, wherein an opening cross-section of the bypass measuring diaphragm ( 20 ) proportional to an opening cross-section of the control orifice ( 18 ). Hydraulic arrangement according to one of claims 1 to 3, wherein the lowering brake valve arrangement ( 12 ) independent of a direction of movement of the hydraulic consumer ( 2 ) in a return flow path ( 10 ) is arranged and the regeneration volume flow independently of a direction of movement of the hydraulic consumer ( 2 ) into a feed flow path ( 6 ) is fed. Hydraulic arrangement according to one of the preceding claims, wherein the lowering brake valve arrangement ( 12 ) a lowering brake valve ( 16 ), whose valve slide ( 26 ) of a closing spring ( 24 ) is acted upon in the direction of a closed position in which a return flow and thus the regeneration volume flow is interrupted. Hydraulic arrangement according to claim 5, wherein an end face of the valve spool ( 26 ) via a throttle ( 36 ) can be acted upon with a pressure medium to aufsteuern. Hydraulic arrangement according to one of claims 5 or 6, wherein the closing spring ( 24 ) in one of a further end face of the valve spool ( 26 ) limited back space ( 44 ), and wherein a fluid connection of the back space ( 44 ) with the pressure medium sink ( 14 ) by means of a shut-off device ( 42 ) is interruptible. Hydraulic arrangement according to claim 7, wherein the shut-off device ( 42 ) a valve body ( 46 ), which by means of a compression spring ( 50 ) is acted upon in the closing direction and by means of one of a pressure medium in the Zulaufströmungspfad ( 6 ) actuatable impact device ( 48 ) is displaceable in the opening direction. Hydraulic arrangement according to claim 7 or 8, wherein the shut-off device ( 42 ) separated from the lowering brake valve ( 16 ) is formed, or in the valve slide ( 26 ) is arranged. Hydraulic arrangement according to claim 8 or 9, wherein the valve body as a pressure balanced slide ( 46 ) is formed with a pressure equalization hole, or is formed as a sealing cone. A hydraulic arrangement according to claim 10, wherein an overlap of the slide ( 46 ) is so large in its bore that leaks occurring over the annular gap between slide ( 46 ) and bore as small as possible. Hydraulic arrangement according to one of claims 4 to 11, wherein by means of a pressure divider arrangement ( 30 ) an intermediate pressure medium is tapped, the pressure acting thereby has a value between one in the return flow path ( 10 ) effective pressure and one in the pressure medium sink ( 14 ) has acting pressure. A hydraulic arrangement according to claim 12, wherein the valve spool ( 26 ) via an intermediate pressure throttle ( 32 ) with pressure medium from an intermediate pressure branch ( 35 ) is acted upon in the closing direction. Hydraulic arrangement according to one of claims 6 to 13, wherein the Aufsteuerdruck for the lowering brake valve ( 16 ) after the metering orifice ( 54 ) from the feed flow path ( 6 ), or between an individual pressure balance ( 52 ) and the metering orifice ( 54 ) from the feed flow path ( 6 ) is tapped. A hydraulic arrangement according to any one of claims 6 to 14, wherein the valve slide ( 26 ) with pressure medium for controlling via a first throttle check valve ( 56 ), which is in the direction of the inflow flow path ( 6 ), and wherein the valve spool ( 26 ) with pressure medium for controlling via a second flow control valve ( 58 ) which is directed in the direction of the return flow path ( 10 ) locks.

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